Hello, how do I know whether I can substitute a cretin servo for one that is being called for in the Arf I purchased? I know the speed and torque play an important roll in that but does brand matter much? If I’m running some digital servos can I run analog ones with them or will the conflict? The servos that are being called to use in my giant scale p-51 mustang are jr ds811 but there discontinued and was wondering if they are just because there is a better one out now from jr. The servos that I have that I would like to use in place of the ds811 is the spektrum ds821 just because I already have them, would those work well in comparison? Thank you in advance for any help and advice on this matter also I’m new to rc universe so was wondering is there a way to make the post I post easy to get back to after I complete it? The only way I found one I posted before was via e-mail but was unable to locate it otherwise.